Process for the production of 1-nitro-anthraquinone-6-carboxylic acid and carbonyl halides thereof



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Milwaukee, Wislgi'tts-.v v vi' .signor to E. I. du Pont de Nemours & Company,

5 claims. (or: 2691-51 -x v This .inventinrelates -tlo the' preparation of carboncompounds and'fmore particularly to the preparationy of l-nitroanthraquinone-S-carboxylicacid 'andits corresponding carbonyl halides. The compound Y 1ynitro-anthraquinone-G-carboxylic'Y-acid has heretotcre beenr produced but bya mostvcomplicated procedure. In 1914 Eckert -(-,Monats. 35,` 289-296`) treated 2-methy1-anthra- 'quinone to' producev ornega-di-bromo-2-methylanthraquinonel.'I The conversion is'indicated by He thereafter hydrolyzedthef di-bromo compound to producze'f-the'1fcorreslioridir'igv anthraquinone-24L -aldehyde 'andi'iritrated this-product to produce 1-nitro-anthraquinonehG-aldehyde according# to the equation: Y

Subsequent oxdation'converted the aldehydegto they corresponding 1-nitro anthraqninone-Smar- Lboxyllc acid) acid'. This invention has'for an 'objectv the preparation of 1-fnitranthraquinone-6-carboxy1ic-acid Vand its correspondingcarbonyllhalides by vimproved processes. Other objects areA the preparation of. these compounds in a very; desirable physical form, and their preparation"inA a high .statey of Apurity.4 Still' further objects are the preparation ofv new chemical 'compounds and'- new chemical processes'. A general advance in the art and other-objectsv whichwill appear hereinafterwas c'ontemplated`.l f

11i-general, the inventionfconiprises .treating ie'rephthaioyl-'ortho-benzoicacid J with; sulphuric acidi followed by a .treatment with'la` nitrating substance and tlnalLv treating the resultant product with a substance capable-of converting'acarboxylsroup to a carbonyl halide.

`The invention. will-.be further.. nderstood `from tion' andispeoiiic examplesinwhich-the parts are givenby weight.E ffl-'.Eximblfl .Teny (10) parts' of 'terephthaloylh'ortho-benzoic acid -were .dissolved` in;r 100.l parts i oflsulphuric acid I(%) and. heidi. at' a'xtemperatureof."150?? C. for 24; hours; afterwhicnlthesoiution wasicooled 'tO.5-I0i C.n Twelvef (121)':'t0114partvsf of-l-a mixture comprising,32%1'nitriciiacid .(HNOQ and 68%fsulphuriczacid i (K280i)i ,hereinafter-,referred .to as'rnixed acidi'wereithenadded torthe'solution. The vtemperature oflthe solution-:Wasi allowed to 'rise fto.- 35A C'.' and-'held therefor onehoun after `which it .was drowned in `water and. nltere'dsf LThe `lter cake was dried andextracted with` 10..'paits L fof ihotiglaciai" acetic ..a.cid.. 'The fin'so1uble.'part Aremaining'was:substantially pure 11'3-'nitroanthrauct was heatcxi.A with fonepartfphosphomis pentachloride andl 6-8 parts of solventi'iaphiha.;,l The resultant 1 nitrov.- anthraquinone 6 carbonyl chloride was filtered fc'oldfwshed with benzene `andfdried. Y The--ll-nitrofanthraquinone-8'car 'boxyli'c acid-is afigrefytogreyyellowcolored-productdssolving in -concentratedsulphuricacidpr forfon'ef hour after which? thesolutiorrwa's-:ooled toA 10-20 C. and 'lfparts` of'mixed' acidfslowl'y vadded. fterfthree hours agitation-at theffsame temperature the rnixture 'was drowned in' {water and filtered"'Thel filtencakewas-then dissolved quinone-6fcarboxylicf acid which? separatedfgout,

dilute alkaliibyjwarniingf tin' thfis- 'insteijrcev sojdum 'hydroxideff allowed "to" 'c0011V vThere'- jafterthe alkali {nietalf-sait/off the l-nitro-anthragwas`r11teredj-'on-.- From "this:alkalimaarl saitlthe .5,59

1'-'nitro"anthranuinone6carboxylb' acid was*` obtained by dissolvingtliealkahmetalstltfin1 water in the ratio of about 275 parts of the alkali metal `salt to 5000--8000 parts of water,` A' Ifhereafter lthe water sglouqn acid-mea 'warjrgsolpiiuricaid :i5

lao

r f.. 'f

(other acids, for example hydrochloric, may be used) to the point where the medium was acid to Congo red and heated at the boiling point for one hour. The solid 1nitroanthraquinone6 carboxylic-'acidywas then filtered'oif.` From the dried 1nitro-anthraquinone-64carboxylic v. acid the corresponding carbonyl chloridewas obtained by heating one part of the same in four parts-51 of ortho-dichloro-benzene :withgone part of phosphorus pentachloride until mthe. conversion-was complete as indicated by-jsolution of v.the 'i acid chloride. y,

Example III acid were dissolved in 100 parts of concentrated su1phuric acid (9e-98%) and Vbeatenai:1,35% After cooling the re-` 140 C. for three hours. sultant mass to 0 C.-5 C. 6-'7 parts of 4nitricl acid (Sp.l Gr. 1.42) were slowly added.v The temperature was allowed to rise to 30A-40 C. and held at this point for 2-4 hours vafter `which time the mixture was drowned in water and filtered. The residue was then 'dissolved in dilute sodium hydroxide and a sufficient amount of sodium chloride added to produce an 8% sodiumchloride solution. The sodium salt of the 1'nitroanthra "quinonef-carboxylic acid, which separated out -wasltered and'washed with 10% sodium chloride solution. k.The free acid was prepared from .the alkali metal. salt by suspendingthe Asame into .about fparts ofwaterand heating to 85-90 C. at which temperature sufficient hydrochloric acid was added to makethis suspension distinctly acidic, in character. .The mass wasV held at about C.- from z-.i'hours-ltered and the cake washed acid free and dried.--j The dried, free acid was lconverted, to;1-nitro-anthraquinone-6,-carf bonyl bromidebytreatment with phosphorus pentabromidev in a, manner similar tothat set out' in'Example I... 'l e. I Y i Ezramplel V onek V(1) part of'thealkaii-metal sait bfinitro-Vanthraquinone-G-carboxylc aCid and 'Y one .part of phosphorus .p entachloride were vadded .to 7 f p arts of ortho-di-'ohlQIOL-benzene.. The whole was thenslowly heatedto 90 C.'100.C. .andlheld iat that temperature for.' one-half Yhour-after whichit was ilteredat yC.: (in1orderlto remove lthe alkali metal chloride present) andthe ltrate cooled to' 10 VCg-l" C. l Thereaftergthe1.-- nitro-anthraquinone--carbonyl chloridewas l- .teredoff and washed first With one part of orthodi-chloro-benzene and ysecond withSZ-Sy parts-.of benzene. The cake was then dried.

. Example? V- Ten-(10) parts of terephthaloyl-ortho-benzoic acid were dissolved in80 parts vof sulphuric acid 1`(100% and heldata temperature of 150 C. for Yone hour. Thesolution was then cooled to .05 C. 'IIen (10) parts of mixed acid were then slowly addedand after onev half hour at 5 C. the solution temperatureraised to 20-25 C. VlThe .temperature was maintained at this. point. for ..8-10 hours after which the 4massuwas drowned `in cold water, andlltered. The residue after drying, wasadded to. 12-15 times itsweight of 7:0 -`boiling glacialacetic acid.y After boiling the refsultant Afor one half to one hour, it'wavs `cooled l -:Emmpzevli.` Ten (10)l parts of` terephthaloylortho-benzoic "acid weredis'solved 88 'parts' ofsulphuric' acid andheld ata temperature of 150 C'. for about two hours, after which the solution was cooled to 10-20" C. and suflicient water added to produce a sulphuric acid concentration of 95%. Thereafter rv,drysodurn nitrite-(1 lf'palts) was added in small p'ortionsf.overl'v hours while maintaining the temperature at 20 C. The mass was then allowed to stand at 2025 C. for 8-10 hours after which it was drowned in cold Water. From thisreaction product the 1nitroanthra quinone-6carboxy1ifcV vacid can be isolated and converted to the'corresponding carbonyl halide Ik I y f inthe manner described in the other examples. Ten (10) parts of terephthaloyl-ortho-benzoic Y 'j Eample VII C `,One hundredeighty-fve parts of terephthaloyl-ortho-benzoic acid were dissolved in 1660 parts of 97% sulphuric acid and held at a temtovrise. to 25-30. C. After holdingthe reactionmass at this temperature for kfi-- hours, water was slowly added, a quantitysuflicient to reduce the sulphuric acid concentration t0 88%. 4 The charge was then agitated for. oneA hour at`25-.C. and filtered. The residue was first washed with 85% sulphuric acid and thenlwashed withA water until acid free. The residue was-then dried and it was found that a yield of 131.5 parts had been obtained. Chlorine gas was passed'fthrough a solution of 73.6 parts of phosphorus trichloride in 525 parts of ortho-dichloro-benzene until; 38.1 parts had been absorbed. Thereafter 131.5 parts of 1-nitroanthraquinone6-carboxylifaci-d, as prepared in preceding part of "example, were added to the phosphorus pentachloride suspen- 'sion in ortho-dichloro-jbenzenef. The; resultant -was heated 90-,100-C. luntil completesolution `had l* taken place `which mass .was *then cooled and filtered at.20 The..,residue ,was.washed with benzene and dried. y ,i

Example Vm sufcient water was Aadded to ,reducethev sulphuric. acidconcentrations@ "83%." The charge was then agitated for one-halffhfour at 25 vC.,

ltered, washed with 80%A sulphuric acidfand nwashed with wateruntiLacidfree.' The" lter cake was then ,dissolved 'indiijutealkan and ,salted out from a'n8% `so'lutionfof'sodium' chlof `ride in themanner Vpreviously kdescribed..fhflhe ,solid material was rfiltered converted tothe "free 1 mtm-munfafiliizfmne;fpearumixylicy acid nl lthe manner previously set out. product was .dried and accedan. ten 'timefsgits Weight` of Ythionyl chloride. Thesuspensiony was reuxed from 1-2 hours and excess .thionyl-,chloridefwas distilled off... Whilethisfproduct isfimveryfgdesirable physical form and ofhigh-@puritmif de,- sired it may be further treated by slurring in six ytimes itsfweight of benzene.:Thebenzenewmay 'beremoved by ltratidnL.' 5 "f1 It will be appreciated that the'1 above-"examples are given merely for the purpose 'off i llustrating "the invention? Wide 'variations' "fromfthe'ffex'a'c't amamos .themselves to.those'lskilled-intheaart;v 1 c As illustrativeof the wide variations vvhichfally within.- the scope of the invention thedollowing maybe mentioned: li In the first steplirrthe-process the best results have bee'nobtain'ed fvvith. 96`100.% sulphuric acid;` Sulphuric; 'acido concentrations vfrom oleumr 102.3% HzSOQl'downzto 95% have been advantageously!employed. In this range the llovver concentrations 'range .ofi 100%- 95% is' preferredf. Goodres'ultsrvare `obtainable with concentrations extendingfbelowlfthe above range, for example 95%-i490%andlower;- Theifollowingtable gives several specific-sets ofrconditions for the firststepinsthe processfwhichzproduces excellent results-'11.' 1 i In each of theabove specific setsA of conditions vone part' of the 'startinglrnaterial I(tere'phthaloylortho-benzoimacid)A issu'secl;y iAll things. considered, the preferred conditions-involveione part. of terephthaloyl-ortho-benzoic acid, 8 parts of 98% H2SO4 and a, reaction temperature of 140-150 C. for one half to one hour.

For the second step in the process an amount of nitric acid somewhat in excess of that required to molecularly combine with the product being treated is used in order that l-nitro group may be introduced into the nucleus. It is possible to prepare a good quality of product in good yield in the absence of an excess of nitric acid. so it is therefore to be understood that the excess is not critical. The excess nitric acid does not appear yto deleteriously affect the reaction since as much as 100% excess nitric acid has been used Without detriment to the process or product.

In the second step in which nitric acid is added to the reaction mass it is preferred that the concentration of the sulphuric acid be 92-96%, more particularly 94%. This percentage range is not critical since the process operates satisfactorily with the use of 100% sulphuric acid. When less concentrated sulphuric acid is used, for example, concentrations of 92% down to 85% HzSOil it is desirable that a larger ratio of sulphuric acid to starting material be used, for example 1'5-25 parts of sulphuric acid to one part of terephthaloylortho-benzoic acid.

The temperature of the step in which the treatment with nitric acid takes place is subject to variation between Wide limits. Preferably a. mixed acid comprising one part of HNOa and 2 parts HzSO. is added to the reaction mass resulting from the first step (said reaction mass being diluted if necessary so that said reaction involves a S33-95% H2804 solution) at a temperature of 0-5 C. over a period of one-half hour. yThe temperature is then allowed to rise slowly over onehalf hour to room temperature, that is, to 2530 C. and then the charge allowed to stand for some time (for example, overnight) It has been found that the nitro group is introduced into the nucleus at about -20 C. and that it is desirable,

although-mot', necessarmr-.that y:the nitric f acidq-be addedslowly.at:anystemperaturefnearorrbelowgthe temperature at` Whichiv the@ introduction of.'Y the nitro group stakes. place The best `results i have .been obtained when thenitriclacid fwasadded-at temperatures below. iii-8 C.` Noaharmi'is done in .raising vthe. temperatureafter'the: addition of: the lnitric acid. f. Good results. have` been obtained with temperatures asl high.` as` 609-80?` C. However, thereis a.; sacrifice of: 'yieldmandr quality :when higher temperatures Vare used and as, an outside ,range forfbestfresults thef addition of nitric acid should-...take placenat. temperaturescbelow 12'.A C.. and .theftemperature 'should notbe allo-wedzto. rise abovefio? C; It is possible that theyield andquality imay. .'beadverselyV .affecteduby heating for extremely long times even at 40 C.

\ In the procedure setout: in Example II.-vvhereinthe l-nitro-anthraquinone-'-carboxylic acid filter cake .Wasf dissolved' inz'dilute caustic alkali, forpurification;v purposes thesodiumsalt of vthe 1.nitro-anthraquinone-carboxylic y.acida may ybe salted out at anytemperatureubetween'01and 60 C. and with the concentration of the v dissolved saltnoris'alts,v (NazSOlyorNaCl, KCl, etc) varying from'zO to 10%.f No'advantage isA gained byfusing more than 8f-1.0%l lvsalt.:concentrations when filtering4 the .1-nitro-anthraquinone--carboxylic acid alkali metalsalt ,below about l,25..-3,5 C. A higher concentration of; saltldoes rvnot :seem to remove any more of the` l-nitro-anthraquinone-G-Lcarboxylic acid alkali metal salt from. the filtrate. f'At. .high temperatures V-proportonately higher. concentrations: of; salty are advantageous.

. In converting. the. alkaliv metal. salt of; Ylgnitroanthraquinone--carboxylic acid to the free acid it is sufficient to acidify to the point where the medium is acid to Congo red provided this concentration is maintained but preferably an excess of acid equal to 4 or 5 times that theoretically necessary to molecularly convert the salt to the acid is used as a safety factor. Under such conditions the concentration of the acid used for the conversion will be 1%-2% in the final mixture before ltration. Such a procedure assures complete conversion of the alkali metal salt to the free acid.

It is to be understood that it is not necessary to start with the 1-nitro-anthraquinone-G-carboxylic acid in order to produce the corresponding acid chloride. The alkali metal salt of the metal acid may be treated to produce the desired final product as indicated in Example IV.

For the purification of the l-nitro-anthraquinone--carboxylic acid by use of alkaline solutions any of the alkalis for example NaOH, NazCOs, KOH, KzCOa, NH4OH, and the like may be used.

As Will be clear from the above description of the invention, it is not limited to the preparation of 1-nitro-anthraquinone-6carbonyl chloride. Any of the 1-nitro-anthraquinone-G-carbonyl halides may be produced by corresponding procedures.

While it is not desired to limit the invention to any particular theory, to aid in the understanding of the same, it may be stated that it is believed that the first step in the process in Which the terephthaloyl-ortho-benzoic acid is treated With sulphuric acid results in the ring closure to an anthraquinone carboxylic acid. In any event during the second step of the process herein described, a nitro group is introduced into the molecule so that the nitro and carboxyl groups are located at ithe l1 and 6` positions of'. the .resultant anthraquinone 'f nucleus. respectively;

This invention has numerous 4advantages as 'will be clearto those skilled inthe art aftera consideration of the above describedlprocesses.

Among these may be mentioned processes .for

-ponents (narrow and delicate operating conditions are always disadvantageous in commercial practice). Y

In addition very .valuable products are produced in desirable attractive'commercially acceptable physicaly forms. and in -high purity.

p Other advantages which merity particular mention are excellent;y yields, elimination of the use of circuitous methods-of preparation, and the like. u y

As many apparently widely `different embodiments of this invention maybe made without departing from the spirit and scope thereof, it is Ato be understood that I do not limit myself to the speciiicembodimentsr thereof except as dened in the appended claims. y

I claim: n

1. As a new and useful chemical process the 'steps which comprise treating, tereplithaloyl-or- ,tho-benzoic' acid with sulphuric acid, treating the resultant product with a nitrating'substance and -treatingfthe product with asubst'ance capable of converting =a carboxyl Lgroup to a carbonyl reaction mass, diluting resultant until a sulphuric acid concentration .of 86% is obtained, iiltering the solid material formed, washing the residue -acid free, adding the washed residue to three parts of ortho-dichloro-benzene,distilling oif` the water present, cooling to 30 C'., adding two parts of yortho-dichloro benzene containing phosphor- 4us-pentachloride and separating y.the l-nitro-anrfthraquinone--carbonyl-chloride formed.

3. As a new and useful chemical process the steps which comprise, treating terephthaloylortho-benzoic acid with sulphuric acid and treating the resultant productjwith a nitrating substance.

4..As a new and useful chemical process the steps which comprise treating terephthaloylortho-benzoic acid with sulphuric acid, treating the resultant product with a nitrating substance and treating the product with a phosphorus pentahalide -to convert the carboxyl group to a carbonyl halide.

5. Process which comprises treating terephthaloyl-ortho-benzoic acid with concentrated sulphuric acid, adding a nitrating substance to the reaction mass, diluting the resultant until a sulphuric acid concentration of 86% is obtained and ltering the, solid material formed.

EARL EDISON BEARD.

CERTIFICATE OF CORRECTION.

Patent No. 1,985,232. December 25, 1934.

EARL EDSON BEARD.

It is hereby certified that error appears in the printed specification 0f the above numbered patent requiring correction as follows: Page 3, second column, line 33, for "high" read higher; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 12th day of March, A. D. 1935.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

